This SNP, a variant in the TP53 gene, is 1 of 25 SNPs reported to represent independently minor, but cumulatively significant, increased risk for breast cancer. [PMID 17341484]

For details of all 25 SNPs in this group, along with the two methods used to calculate overall risk estimates for breast cancer, refer to the SNPedia breast cancer entry.

For this particular SNP, the G allele encodes an arginine at position 72 of the protein (where there's normally a proline), and the SNP is commonly called the Arg72 variant, although P72R and Arg72Pro are also common in the literature.

[PMID 18256523] Minor allele homozygotes, i.e. rs1042522(C;C) genotypes, live on average 3 years longer than major allele (G;G) homozygotes, based on a study of 9,200+ Danish individuals. The increased longevity is speculated to be related to the increased apoptosis seen for this gain of function SNP, presumably due to "increased robustness" during the period of treatment after the diagnosis of life-threatening diseases such as cancer of certain types.

23andMe blog African Americans with rs1042522(G;G) in the p53 gene were 2.15 times more likely to die of colorectal cancer than those with one or no copies of a G at this SNP. In Caucasians there was no association between survival and rs1042522.

23andMe blog rs1042522(C) might have had an easier time conceiving in colder temperatures

10.1073/pnas.0904280106 The P72 allele was found to be significantly enriched over the R72 allele among in vitro fertilization (IVF) patients. The P72 allele serves as a risk factor for implantation failure. LIF levels are significantly lower in cells with the P72 allele than in cells with the R72 allele, which may contribute to the decreased implantation and fertility associated with the P72 allele.

[PMID 19367277] Patients with variant TP53 genotypes either for the Arg72Pro or the PIN3 polymorphism were at increased risk of telangiectasia, a late skin side effect of radiotherapy following breast-conserving surgery. Odds ratios were 1.66 for 72Pro carriers and 1.95 for PIN3 A2 allele carriers. Carrying both variant alleles led to a doubling of risk.

Defects in TP53 are a cause of choroid plexus papilloma (MIM:260500). Choroid plexus papilloma is a slow-growing benign tumor of the choroid plexus that often invades the leptomeninges. In children it is usually in a lateral ventricle but in adults it is more often in the fourth ventricle. Hydrocephalus is common, either from obstruction or from tumor secretion of cerebrospinal fluid. If it undergoes malignant transformation it is called a choroid plexus carcinoma. Primary choroid plexus tumors are rare and usually occur in early childhood.

[PMID 19423538] Common Genetic Variation in TP53 and Risk of Human Papillomavirus Persistence and Progression to CIN3/Cancer Revisited

[PMID 19471604] Lack of association between p53 gene polymorphisms and primary open angle glaucoma in the Japanese population

[PMID 19505915] Association of Genetic Polymorphisms, mRNA Expression of p53 and p21 with Chronic Benzene Poisoning in a Chinese Occupational Population

This is a common variant was first reported as a polymorphism. It has since had mixed associations with cancer: Storey et al. conclude a 7x *increased* risk of HPV cancer for homozygotes vs hets, but Jones et al. find a 1.98x *decreased* risk for colorectal cancer. This variant may have significant impact on particular cancers, but it is unclear what effect it has on the overall burden of cancer.

[PMID 23192612] Association of common WRAP 53 variant with ovarian cancer risk in the Polish population

[PMID 23936089] Polymorphisms in DNA-Repair Genes in a Cohort of Prostate Cancer Patients from Different Areas in Spain: Heterogeneity between Populations as a Confounding Factor in Association Studies